1. Field of the Invention
The present invention relates to an image forming apparatus applied to a copy machine, a printer, a facsimile device, or the like, and in particular, to an image forming apparatus that detects a correction patch to perform image stabilizing processing.
2. Description of the Related Art
There has been widely used an electrophotographic image forming apparatus in which a toner image formed on a photoreceptor is transferred to a sheet or other transfer materials via a transfer section such as an intermediate transfer belt, the sheet having the toner image transferred thereon is heated and pressurized in a fixing section, and the toner image is fixed on the sheet.
The fixing section used in such an image forming apparatus includes, for example, a fixing member constituted of a heating roller, and a pressurizing member disposed in a position facing the fixing member and including a counter roller that is pressed against the fixing member side while rotating. In addition, the sheet that carries an unfixed toner image passes through a nip portion between the fixing member and the pressurizing member, whereby the toner image is fixed on the sheet.
Conventionally, there is known an image forming apparatus in which a sensor for image stabilization is disposed on the downstream side of a transfer section on an intermediate transfer belt, and image stabilizing processing is performed, in order to stabilize quality of images. This image forming apparatus creates a correction patch formed by toner on the intermediate transfer belt, and detects this correction patch with the sensor for image stabilization, thereby correcting imaging conditions for forming images. In addition, when the correction patch passes through between the intermediate transfer belt and a transfer roller (transfer nip portion), the transfer roller is spaced apart from the intermediate transfer belt in order to prevent a part of the toner of the correction patch from adhering to the transfer roller.
Furthermore, an image forming apparatus described in Patent Literature 1 proposes a technique of making a system speed of image stabilizing processing slower than that of image forming processing in performing the image stabilizing processing, in order to prevent toner from spattering.